Patent Application
20190248156
The present invention relates to thermal printers. More particularly, it relates to a method and device for protecting the print head of a thermal printer.
Thermal printers are used for many different label printing operations. They are also used in some industries as label dispensers as well as printers. The direct thermal print heads in these printers are subject to wear when printing labels, and also when not printing labels (i.e., when the printer is being used as a label dispenser for already printed labels) and the thermal printer portion is turned off. In either instance, the abrasive action or friction of the labels or other material traveling against the surface of the direct thermal print head surface will cause damage to the print head. In fact, this abrasive action/friction is the main cause of damage to the thermal print head. Thus, when using the thermal printer as a label dispenser for already printed labels, there is a need to protect the print head from this abrasive action.
The present inventions addresses the shortfalls of existing thermal printing machines by providing a protective cover to the direct thermal print head to prevent head wear when the printer is being used to dispense already printed labels.
According to one implementation, the thermal printer includes a print head assembly having a printhead, and a cover removably disposed over the printhead and configured to prevent the same from being exposed to a thermal material passing over the same during label dispensing.
According to a further implementation, the printhead cover has a low coefficient of friction and is in the form of a sleeve that fits over the entire printhead assembly.
Other aspects and features of the present principles will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the present principles, for which reference should be made to the appended claims. It should be further understood that the drawings are not necessarily drawn to scale and that, unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein.
In the drawings wherein like reference numerals denote similar components throughout the views:
In accordance with one embodiment, the coefficient of friction of the protective sleeve is very low. Those of skill in the art will appreciate that the coefficient of friction for different materials can be drastically different. As such, and as a guideline, the coefficient of friction for most materials is between 0 and 1, with 0 being the lowest (i.e., no friction). According to the present principles, the printhead cover or sleeve has a low coefficient of friction, preferably 0.3 or less.
In accordance with one exemplary embodiment, the protective sleeve 40 is made of an ultra high molecular weight flexible tape (UHMW) having a coefficient of friction in a range of 0.10-0.20, and has a length or size L2 that does not necessarily have to equal the length or size L1 of the printhead 14. In fact, the length or size L2 can be dictated by the size or width of the label run (thermal material) 16 that would be passing over the printhead 14. Thus, L2 will generally be less than L1 in this instance, but L2 must always be larger than the width of the label run or thermal material 16.
In accordance with other contemplated embodiments, the protective sleeve 40 can be replaced with other devices that operate in the same manner to shield the printhead 14 from the abrasive action caused by the labels moving across the same.
Examples of such other embodiments include a clip on cover that clips onto the printhead 14 or the assembly 12. In this embodiment, it is envisioned that the clips would engage another portion of the printhead assembly 12 such that a thin strip of material covers the printhead 14. Another embodiment would include a strip having a removable adhesive that covers the print elements of the print head 14. This strip could be disposable and be a single use type of product. According to yet another embodiment, the printer could be modified to allow the roller assembly 34 which applies pressure on the back of the thermal material (i.e., label run 16) to be retracted away from the printhead 14 such that the thermal material 16 does not come into contact with the same when operating the printer as a label dispenser.
In accordance with other embodiment shown in
While there have been shown, described and pointed out fundamental novel features of the present principles, it will be understood that various omissions, substitutions and changes in the form and details of the methods described and devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the same. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the present principles. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or implementation of the present principles may be incorporated in any other disclosed, described or suggested form or implementation as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.
This application is a continuation application of U.S. patent application Ser. No. 15/839,267, filed on Dec. 12, 2017, from which this application claims priority. U.S. patent application Ser. No. 15/839,267 is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 15839267 | Dec 2017 | US |
| Child | 16393435 | US |
